A 16-year-old boy has an osteosarcoma of the distal femur confirmed on biopsy. Staging CT shows no distant metastases. According to the Musculoskeletal Tumor Society (MSTS) staging system, the lesion is stage IIB (high-grade extracompartmental). The preferred surgical margin for limb salvage surgery is:

• A Intralesional margin — curettage is adequate for osteosarcoma
• B Marginal margin — along the reactive zone
• C Radical margin — entire bone with all attached musculature
• D Wide margin — en-bloc resection with a cuff of normal tissue beyond the reactive zone ✓

Explanation

For high-grade (stage II) sarcomas including osteosarcoma, the minimum acceptable oncologic margin is a wide surgical margin — en-bloc resection removing the tumor with a surrounding cuff of histologically normal tissue, well outside the reactive pseudocapsule. Intralesional and marginal margins leave residual tumor cells and are associated with high local recurrence rates. Radical margins (entire anatomical compartment) are rarely feasible in the distal femur and offer no local control benefit over wide margins when combined with neoadjuvant chemotherapy. Wide margins combined with neoadjuvant/adjuvant chemotherapy (MAP — methotrexate, doxorubicin, cisplatin) are the current standard.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

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Written and medically reviewed by the StethoPrep medical team.